A loop shaped diving board spring of resin impregnated glass fiber



March 3, 1970 A. H. Bos'rRoM ET AL 3,498,695

K LOOP SHAPED DIVING-BOARD SPRING 0F RESIN IMPREGNATED GLASS FIBER FledJune 22, 1967 l| Zl United States Patent O 3,498,606 A LOOP SHAPED DIVING BGARD SPRING F RESIN IMPREGNATED GLASS FIBER Alan H. Bostrom, Wauwatosa, and Jack Lowrie McLarty, Milwaukee, Wis., assignors, by mesne assignments, to Universal Oil Products Company, Des Plaines, Ill., a corporation of Delaware Filed June 22, 1967, Ser. No. 647,984 Int. Cl. A63b 5/08 U.S. Cl. 272-66 2 Claims ABSTRACT 0F THE DISCLOSURE The disclosed diving board utilizes a spring board which may extend over a body of water and which is fixed to a solid support by a loop-shaped spring which is formed of a resin impregnated and cured glass liber winding. The spring rate of the spring can be varied by changing the width of the area through which the spring Vis fixed to the support.

This invention pertains to improvements in diving boards.

Background of the invention The field of invention encompasses the area of spring boards and the area of resin impregnated glass fiber springs.

In the diving boards of the prior art the fixed end of the spring board was either rigidly fixed to a permanent sup-` port, in which case the necessary resiliency was provided by the freely extending end of the board, or the fixed end was pivotally secured to the permanent support and the resiliency was provided by various spring devices interposed between the board and the support at a location intermediate the ends of the board.

Summary The present invention resides n the provision of a diving board which has a movable spring biased fulcrum point and thereby provides effective spring to the diving board at any point along the board.

Description of the drawings FIG. 1 is a perspective view of the diving board embodying the present invention; and

FIG. 2 is a top view, taken on line 2-2 of FIG. 1, showing the spring securing and adjustment structure, with parts being broken away for the sake of illustration.

Referring to the drawing in detail, the diving board is comprised of a spring board which in itself may be made of any suitable material, such as wood, reinforced plastic, metal or other materials commonly employed in the manufacture of spring boards, and a loop-shaped spring 12 which is interposed between the fixed end 14 of the spring board and the concrete slab which forms a permanent support for the diving board.

The spring 12 is a glass fiber winding which is manufactured by-winding a continuous resin impregnated ber (the fiber being itself comprised of a plurality of glass fiber strands) to form a closed loop design and of curing the winding after it has attained the desired contour and wall thickness. The orientation of the fibers may be constant or varied or a combination of orientations may be employed. The fibers are maintained under slight tension during the winding process and therefore any load which is applied to the spring acts directly on the fibers instead of being transmitted thereto through the resin or bonding medium. This feature assures fairly even distribution of the load carrying ability of the fibers. The ratio of Patented Mar. 3, 1970 ICC resin to glass for the illustrated application is between 15% resin and 85% glass and 35% resin and 65% glass.

The oval spring 12 provides an opposing spring bias to any force which tends to deform the spring from its neutral shape (FIG. 1). Thus, as the spring is loaded at point A, as would be the case when a diver would start his advance towards the free end of the board, the front and back arcs of the loop, 16 and 18 respectively, are compressed thereby loading the fibers on the inside of the winding in compression and those on the outside of the winding in tension. As the diver advances towards the free end of the board (when the board is loaded at B) the front arc 16 of the loop is further compressed but the back arc 18 is opened past its neutral position and the load kon the fibers in that portion of the loop is reversed. Also, the fibers of the Winding provide a biased opposition to torsional loading of the spring and therefore any offcenter loading is effectively counteracted by the spring. The low ymodulus (3 to 6 million with fiber glass fibers) plus high strength (tensile above 100,000 p.s.i. and flexural stress above 80,000 p.s.i.) in combination with high impact strength and high notch sensitivity values provide fatigue resistance and load carrying ability above that for spring steel. Further, the fiber glass spring is corrosion resistant and may be pigmented to provide any color.

Because the full load imposed on the spring board is always transferred to the spring in its entirety, a diving board of this design is capable of providing more resiliency or spring than comparable size diving boards known heretofore.

A stop 28 may be provided to limit the downward travel of the board. The stop 28 is of particular significance if the diving board is intended for use by children as well as adults, in which case the board will not deflect sufficiently far to hit the stop when the board is used by a child but will hit the stop when it is used by an adult. In the latter instance the board will tend to pivot around the stop thus causing the front arc 10 as well as the back are 18 to expand beyond its relaxed shape. The stop may be of somewhat resilient material.

The spring is attached to the spring board by a holding plate 20 and to the concrete support by an adjustable holding plate 22. The holes required in the winding for the bolts 24 are wound-in, which is accomplished by dellecting the fibers around pins which are provided on the winding -mandrel during the winding process. Alternatively pointed dowels may be driven through the winding in the appropriate locations before the curing operation. In either event, the bolt apertures are provided by deflection ofthe fibers around the periphery of the aperture without causing severance of the fibers. This feature assures the maintenance of high fatigue life, which would not be the case if it were made by a method which would cause cutting of the fibers and would thus result in stress raisers which would decrease the fatigue life of the spring.

The spring is made stiffer' if the holding plate 22 is expanded from the position shown in the drawings and the spring is made softer if the width of the holding plate is reduced. This is accomplished by providing elongated slots 26 for the belts which hold the two segments of the holding plate 22 and by providing the tongue-groove connecting mechanism between the two segments of the plate.

In providing diving boards as described above, it should be noted that the spring force depends upon the thickness of the winding, the particular radii of the arcs 16 and 18 by the length of the spring itself, and by the contour of the plate 22. 'I'hese factors must be, of course, taken into consideration when the board is designed. Further, the spring force may be varied by changing theheight and fore and aft position of the stop 28.

Although but one embodiment of the present invention 3 has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be -made therein without departing from the spirit of the invention or from the scope of the appended claims.

We claim: 1. A diving board comprising: a generally horizontally extending elongated spring board; spring means attached to said spring board at one end thereof and adapted to be attached to a permanent support at the side of a body of water to permit the other end to be so positioned in respect to such body as to permit a diver to advance from said one end towards the other end and to dive from said other end; said spring means being the sole support for said spring board to thereby provide biased vertical movement of said spring board in respect to said support when said spring board is loaded at said one end and to permit biased pivotal movement of said spring board generally around its connection to said spring means When said spring board is loaded at said other end; said spring means is comprised of a loop-shaped winding of resin-impregnated and cured glass bers and including two arc-shaped resilient sections With one section being closer to said one end of the spring board than the other spring means section, with both of said sections being loaded in compression when said spring board is loaded at said one end and with 3 said one spring means section being loaded in tension and said other spring means section being fur- 4 ther loaded in compression when said spring board is loaded at said other end, said sections providing a biased opposing force to the compression and expansion beyond their neutral state;

attaching means for attaching said spring means to a said restraining means includes an adjustment mechanism which permits variance in the width (fore and aft in respect to said spring board) of said restraining means to thereby permit variance in the spring rate of said spring means.

2. A diving board according to claim 1 wherein the glass fibers of said winding are deilected around said aper- 20 tures without interruption of the continuity of said bers.

References Cited UNITED STATES PATENTS GEORGE I. MARLO, Primary Examiner R. W. DIAZ, JR., Assistant Examiner 

